[pve-devel] [PATCH common] Add AbstractConfig base class
Fabian Grünbichler
f.gruenbichler at proxmox.com
Wed Mar 2 13:56:26 CET 2016
This class contains common code formerly duplicated in
PVE::LXC and PVE::QemuServer, as well as abstract methods
that must be implemented for LXC and Qemu seperately.
Currently implemented in PVE::LXC::Config, Qemu refactoring
will follow.
---
This patch only takes effect when the related patch series for
pve-container is applied as well.
src/Makefile | 3 +-
src/PVE/AbstractConfig.pm | 627 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 629 insertions(+), 1 deletion(-)
create mode 100644 src/PVE/AbstractConfig.pm
diff --git a/src/Makefile b/src/Makefile
index 5e50005..92a323d 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -20,7 +20,8 @@ LIB_SOURCES= \
INotify.pm \
Tools.pm \
AbstractMigrate.pm \
- Exception.pm
+ Exception.pm \
+ AbstractConfig.pm
all:
diff --git a/src/PVE/AbstractConfig.pm b/src/PVE/AbstractConfig.pm
new file mode 100644
index 0000000..be6eb5c
--- /dev/null
+++ b/src/PVE/AbstractConfig.pm
@@ -0,0 +1,627 @@
+package PVE::AbstractConfig;
+
+use strict;
+use warnings;
+
+use PVE::Tools qw(lock_file lock_file_full);
+use PVE::INotify;
+
+my $nodename = PVE::INotify::nodename();
+
+# Printable string, currently either "VM" or "CT"
+sub guest_type {
+ my ($class) = @_;
+ die "abstract method - implement me ";
+}
+
+sub __config_max_unused_disks {
+ my ($class) = @_;
+
+ die "implement me - abstract method\n";
+}
+
+# Path to the flock file for this VM/CT
+sub config_file_lock {
+ my ($class, $vmid) = @_;
+ die "abstract method - implement me";
+}
+
+# Relative config file path for this VM/CT in CFS
+sub cfs_config_path {
+ my ($class, $vmid, $node) = @_;
+ die "abstract method - implement me";
+}
+
+# Absolute config file path for this VM/CT
+sub config_file {
+ my ($class, $vmid, $node) = @_;
+
+ my $cfspath = $class->cfs_config_path($vmid, $node);
+ return "/etc/pve/$cfspath";
+}
+
+# Read and parse config file for this VM/CT
+sub load_config {
+ my ($class, $vmid, $node) = @_;
+
+ $node = $nodename if !$node;
+ my $cfspath = $class->cfs_config_path($vmid, $node);
+
+ my $conf = PVE::Cluster::cfs_read_file($cfspath);
+ die "Configuration file '$cfspath' does not exist\n"
+ if !defined($conf);
+
+ return $conf;
+}
+
+# Generate and write config file for this VM/CT
+sub write_config {
+ my ($class, $vmid, $conf) = @_;
+
+ my $cfspath = $class->cfs_config_path($vmid);
+
+ PVE::Cluster::cfs_write_file($cfspath, $conf);
+}
+
+# Lock config file using flock, run $code with @param, unlock config file.
+# $timeout is the maximum time to aquire the flock
+sub lock_config_full {
+ my ($class, $vmid, $timeout, $code, @param) = @_;
+
+ my $filename = $class->config_file_lock($vmid);
+
+ my $res = lock_file($filename, $timeout, $code, @param);
+
+ die $@ if $@;
+
+ return $res;
+}
+
+# Lock config file using flock, run $code with @param, unlock config file.
+# $timeout is the maximum time to aquire the flock
+# $shared eq 1 creates a non-exclusive ("read") flock
+sub lock_config_mode {
+ my ($class, $vmid, $timeout, $shared, $code, @param) = @_;
+
+ my $filename = $class->config_file_lock($vmid);
+
+ my $res = lock_file_full($filename, $timeout, $shared, $code, @param);
+
+ die $@ if $@;
+
+ return $res;
+}
+
+# Lock config file using flock, run $code with @param, unlock config file.
+sub lock_config {
+ my ($class, $vmid, $code, @param) = @_;
+
+ return $class->lock_config_full($vmid, 10, $code, @param);
+}
+
+# Checks whether the config is locked with the lock parameter
+sub check_lock {
+ my ($class, $conf) = @_;
+
+ die $class->guest_type()." is locked ($conf->{lock})\n" if $conf->{lock};
+}
+
+# Returns whether the config is locked with the lock parameter, also checks
+# whether the lock value is correct if the optional $lock is set.
+sub has_lock {
+ my ($class, $conf, $lock) = @_;
+
+ return $conf->{lock} && (!defined($lock) || $lock eq $conf->{lock});
+}
+
+# Sets the lock parameter for this VM/CT's config to $lock.
+sub set_lock {
+ my ($class, $vmid, $lock) = @_;
+
+ my $conf;
+ $class->lock_config($vmid, sub {
+ $conf = $class->load_config($vmid);
+ $class->check_lock($conf);
+ $conf->{lock} = $lock;
+ $class->write_config($vmid, $conf);
+ });
+ return $conf;
+}
+
+# Removes the lock parameter for this VM/CT's config, also checks whether
+# the lock value is correct if the optional $lock is set.
+sub remove_lock {
+ my ($class, $vmid, $lock) = @_;
+
+ $class->lock_config($vmid, sub {
+ my $conf = $class->load_config($vmid);
+ if (!$conf->{lock}) {
+ die "no lock found trying to remove lock '$lock'\n";
+ } elsif (defined($lock) && $conf->{lock} ne $lock) {
+ die "found lock '$conf->{lock}' trying to remove lock '$lock'\n";
+ }
+ delete $conf->{lock};
+ $class->write_config($vmid, $conf);
+ });
+}
+
+# Checks whether protection mode is enabled for this VM/CT.
+sub check_protection {
+ my ($class, $conf, $err_msg) = @_;
+
+ if ($conf->{protection}) {
+ die "$err_msg - protection mode enabled\n";
+ }
+}
+
+# Adds an unused volume to $config, if possible.
+sub add_unused_volume {
+ my ($class, $config, $volid) = @_;
+
+ my $key;
+ for (my $ind = $class->__config_max_unused_disks() - 1; $ind >= 0; $ind--) {
+ my $test = "unused$ind";
+ if (my $vid = $config->{$test}) {
+ return if $vid eq $volid; # do not add duplicates
+ } else {
+ $key = $test;
+ }
+ }
+
+ die "Too many unused volumes - please delete them first.\n" if !$key;
+
+ $config->{$key} = $volid;
+
+ return $key;
+}
+
+# Returns whether the template parameter is set in $conf.
+sub is_template {
+ my ($class, $conf) = @_;
+
+ return 1 if defined $conf->{template} && $conf->{template} == 1;
+}
+
+# Checks whether $feature is availabe for the referenced volumes in $conf.
+# Note: depending on the parameters, some volumes may be skipped!
+sub has_feature {
+ my ($class, $feature, $conf, $storecfg, $snapname, $running, $backup_only) = @_;
+ die "implement me - abstract method\n";
+}
+
+# Internal snapshots
+
+# NOTE: Snapshot create/delete involves several non-atomic
+# actions, and can take a long time.
+# So we try to avoid locking the file and use the 'lock' variable
+# inside the config file instead.
+
+# Save the vmstate (RAM).
+sub __snapshot_save_vmstate {
+ my ($class, $vmid, $conf, $snapname, $storecfg) = @_;
+ die "implement me - abstract method\n";
+}
+
+# Check whether the VM/CT is running.
+sub __snapshot_check_running {
+ my ($class, $vmid) = @_;
+ die "implement me - abstract method\n";
+}
+
+# Check whether we need to freeze the VM/CT
+sub __snapshot_check_freeze_needed {
+ my ($sself, $vmid, $config, $save_vmstate) = @_;
+ die "implement me - abstract method\n";
+}
+
+# Freeze or unfreeze the VM/CT.
+sub __snapshot_freeze {
+ my ($class, $vmid, $unfreeze) = @_;
+
+ die "abstract method - implement me\n";
+}
+
+# Create the volume snapshots for the VM/CT.
+sub __snapshot_create_vol_snapshot {
+ my ($class, $vmid, $vs, $volume, $snapname) = @_;
+
+ die "abstract method - implement me\n";
+}
+
+# Remove a drive from the snapshot config.
+sub __snapshot_delete_remove_drive {
+ my ($class, $snap, $remove_drive) = @_;
+
+ die "abstract method - implement me\n";
+}
+
+# Delete the vmstate file/drive
+sub __snapshot_delete_vmstate_file {
+ my ($class, $snap, $force) = @_;
+
+ die "abstract method - implement me\n";
+}
+
+# Delete a volume snapshot
+sub __snapshot_delete_vol_snapshot {
+ my ($class, $vmid, $vs, $volume, $snapname) = @_;
+
+ die "abstract method - implement me\n";
+}
+
+# Checks whether a volume snapshot is possible for this volume.
+sub __snapshot_rollback_vol_possible {
+ my ($class, $volume, $snapname) = @_;
+
+ die "abstract method - implement me\n";
+}
+
+# Rolls back this volume.
+sub __snapshot_rollback_vol_rollback {
+ my ($class, $volume, $snapname) = @_;
+
+ die "abstract method - implement me\n";
+}
+
+# Stops the VM/CT for a rollback.
+sub __snapshot_rollback_vm_stop {
+ my ($class, $vmid) = @_;
+
+ die "abstract method - implement me\n";
+}
+
+# Start the VM/CT after a rollback with restored vmstate.
+sub __snapshot_rollback_vm_start {
+ my ($class, $vmid, $vmstate, $forcemachine);
+
+ die "abstract method - implement me\n";
+}
+
+# Iterate over all configured volumes, calling $func for each key/value pair.
+sub __snapshot_foreach_volume {
+ my ($class, $conf, $func) = @_;
+
+ die "abstract method - implement me\n";
+}
+
+# Copy the current config $source to the snapshot config $dest
+sub __snapshot_copy_config {
+ my ($class, $source, $dest) = @_;
+
+ foreach my $k (keys %$source) {
+ next if $k eq 'snapshots';
+ next if $k eq 'snapstate';
+ next if $k eq 'snaptime';
+ next if $k eq 'vmstate';
+ next if $k eq 'lock';
+ next if $k eq 'digest';
+ next if $k eq 'description';
+ next if $k =~ m/^unused\d+$/;
+
+ $dest->{$k} = $source->{$k};
+ }
+};
+
+# Apply the snapshot config $snap to the config $conf (rollback)
+sub __snapshot_apply_config {
+ my ($class, $conf, $snap) = @_;
+
+ # copy snapshot list
+ my $newconf = {
+ snapshots => $conf->{snapshots},
+ };
+
+ # keep description and list of unused disks
+ foreach my $k (keys %$conf) {
+ next if !($k =~ m/^unused\d+$/ || $k eq 'description');
+ $newconf->{$k} = $conf->{$k};
+ }
+
+ $class->__snapshot_copy_config($snap, $newconf);
+
+ return $newconf;
+}
+
+# Prepares the configuration for snapshotting.
+sub __snapshot_prepare {
+ my ($class, $vmid, $snapname, $save_vmstate, $comment) = @_;
+
+ my $snap;
+
+ my $updatefn = sub {
+
+ my $conf = $class->load_config($vmid);
+
+ die "you can't take a snapshot if it's a template\n"
+ if $class->is_template($conf);
+
+ $class->check_lock($conf);
+
+ $conf->{lock} = 'snapshot';
+
+ die "snapshot name '$snapname' already used\n"
+ if defined($conf->{snapshots}->{$snapname});
+
+ my $storecfg = PVE::Storage::config();
+ die "snapshot feature is not available\n"
+ if !$class->has_feature('snapshot', $conf, $storecfg, undef, undef, $snapname eq 'vzdump');
+
+ $snap = $conf->{snapshots}->{$snapname} = {};
+
+ if ($save_vmstate && $class->__snapshot_check_running($vmid)) {
+ $class->__snapshot_save_vmstate($vmid, $conf, $snapname, $storecfg);
+ }
+
+ $class->__snapshot_copy_config($conf, $snap);
+
+ $snap->{snapstate} = "prepare";
+ $snap->{snaptime} = time();
+ $snap->{description} = $comment if $comment;
+
+ $class->write_config($vmid, $conf);
+ };
+
+ $class->lock_config($vmid, $updatefn);
+
+ return $snap;
+}
+
+# Commits the configuration after snapshotting.
+sub __snapshot_commit {
+ my ($class, $vmid, $snapname) = @_;
+
+ my $updatefn = sub {
+
+ my $conf = $class->load_config($vmid);
+
+ die "missing snapshot lock\n"
+ if !($conf->{lock} && $conf->{lock} eq 'snapshot');
+
+ my $snap = $conf->{snapshots}->{$snapname};
+ die "snapshot '$snapname' does not exist\n" if !defined($snap);
+
+ die "wrong snapshot state\n"
+ if !($snap->{snapstate} && $snap->{snapstate} eq "prepare");
+
+ delete $snap->{snapstate};
+ delete $conf->{lock};
+
+ $conf->{parent} = $snapname;
+
+ $class->write_config($vmid, $conf);
+ };
+
+ $class->lock_config($vmid, $updatefn);
+}
+
+# Creates a snapshot for the VM/CT.
+sub snapshot_create {
+ my ($class, $vmid, $snapname, $save_vmstate, $comment) = @_;
+
+ my $snap = $class->__snapshot_prepare($vmid, $snapname, $save_vmstate, $comment);
+
+ $save_vmstate = 0 if !$snap->{vmstate};
+
+ my $conf = $class->load_config($vmid);
+
+ my ($running, $freezefs) = $class->__snapshot_check_freeze_needed($vmid, $conf, $snap->{vmstate});
+
+ my $drivehash = {};
+
+ eval {
+ if ($freezefs) {
+ $class->__snapshot_freeze($vmid, 0);
+ }
+
+ $class->__snapshot_foreach_volume($snap, sub {
+ my ($vs, $volume) = @_;
+
+ $class->__snapshot_create_vol_snapshot($vmid, $vs, $volume, $snapname);
+ $drivehash->{$vs} = 1;
+ });
+ };
+ my $err = $@;
+
+ if ($running) {
+ if ($freezefs) {
+ $class->__snapshot_freeze($vmid, 1);
+ }
+ }
+
+ if ($err) {
+ warn "snapshot create failed: starting cleanup\n";
+ eval { $class->snapshot_delete($vmid, $snapname, 1, $drivehash); };
+ warn "$@" if $@;
+ die "$err\n";
+ }
+
+ $class->__snapshot_commit($vmid, $snapname);
+}
+
+# Deletes a snapshot.
+# Note: $drivehash is only set when called from snapshot_create.
+sub snapshot_delete {
+ my ($class, $vmid, $snapname, $force, $drivehash) = @_;
+
+ my $prepare = 1;
+
+ my $snap;
+ my $unused = [];
+
+ my $unlink_parent = sub {
+ my ($confref, $new_parent) = @_;
+
+ if ($confref->{parent} && $confref->{parent} eq $snapname) {
+ if ($new_parent) {
+ $confref->{parent} = $new_parent;
+ } else {
+ delete $confref->{parent};
+ }
+ }
+ };
+
+ my $updatefn = sub {
+ my ($remove_drive) = @_;
+
+ my $conf = $class->load_config($vmid);
+
+ if (!$drivehash) {
+ $class->check_lock($conf);
+ die "you can't delete a snapshot if vm is a template\n"
+ if $class->is_template($conf);
+ }
+
+ $snap = $conf->{snapshots}->{$snapname};
+
+ die "snapshot '$snapname' does not exist\n" if !defined($snap);
+
+ # remove parent refs
+ if (!$prepare) {
+ &$unlink_parent($conf, $snap->{parent});
+ foreach my $sn (keys %{$conf->{snapshots}}) {
+ next if $sn eq $snapname;
+ &$unlink_parent($conf->{snapshots}->{$sn}, $snap->{parent});
+ }
+ }
+
+ if ($remove_drive) {
+ $class->__snapshot_delete_remove_drive($snap, $remove_drive);
+ }
+
+ if ($prepare) {
+ $snap->{snapstate} = 'delete';
+ } else {
+ delete $conf->{snapshots}->{$snapname};
+ delete $conf->{lock} if $drivehash;
+ foreach my $volid (@$unused) {
+ $class->add_unused_volume($conf, $volid);
+ }
+ }
+
+ $class->write_config($vmid, $conf);
+ };
+
+ $class->lock_config($vmid, $updatefn);
+
+ # now remove vmstate file
+ if ($snap->{vmstate}) {
+ $class->__snapshot_delete_vmstate_file($snap, $force);
+
+ # save changes (remove vmstate from snapshot)
+ $class->lock_config($vmid, $updatefn, 'vmstate') if !$force;
+ };
+
+ # now remove all volume snapshots
+ $class->__snapshot_foreach_volume($snap, sub {
+ my ($vs, $volume) = @_;
+
+ return if $snapname eq 'vzdump' && $vs ne 'rootfs' && !$volume->{backup};
+ if (!$drivehash || $drivehash->{$vs}) {
+ eval { $class->__snapshot_delete_vol_snapshot($vmid, $vs, $volume, $snapname); };
+ if (my $err = $@) {
+ die $err if !$force;
+ warn $err;
+ }
+ }
+
+ # save changes (remove mp from snapshot)
+ $class->lock_config($vmid, $updatefn, $vs) if !$force;
+ push @$unused, $volume->{volume};
+ });
+
+ # now cleanup config
+ $prepare = 0;
+ $class->lock_config($vmid, $updatefn);
+}
+
+# Rolls back to a given snapshot.
+sub snapshot_rollback {
+ my ($class, $vmid, $snapname) = @_;
+
+ my $prepare = 1;
+
+ my $storecfg = PVE::Storage::config();
+
+ my $conf = $class->load_config($vmid);
+
+ my $get_snapshot_config = sub {
+
+ die "you can't rollback if vm is a template\n" if $class->is_template($conf);
+
+ my $res = $conf->{snapshots}->{$snapname};
+
+ die "snapshot '$snapname' does not exist\n" if !defined($res);
+
+ return $res;
+ };
+
+ my $snap = &$get_snapshot_config();
+
+ $class->__snapshot_foreach_volume($snap, sub {
+ my ($vs, $volume) = @_;
+
+ $class->__snapshot_rollback_vol_possible($volume, $snapname);
+ });
+
+ my $updatefn = sub {
+
+ $conf = $class->load_config($vmid);
+
+ $snap = &$get_snapshot_config();
+
+ die "unable to rollback to incomplete snapshot (snapstate = $snap->{snapstate})\n"
+ if $snap->{snapstate};
+
+ if ($prepare) {
+ $class->check_lock($conf);
+ $class->__snapshot_rollback_vm_stop($vmid);
+ }
+
+ die "unable to rollback vm $vmid: vm is running\n"
+ if $class->__snapshot_check_running($vmid);
+
+ if ($prepare) {
+ $conf->{lock} = 'rollback';
+ } else {
+ die "got wrong lock\n" if !($conf->{lock} && $conf->{lock} eq 'rollback');
+ delete $conf->{lock};
+ }
+
+ # machine only relevant for Qemu
+ my $forcemachine;
+
+ if (!$prepare) {
+ my $has_machine_config = defined($conf->{machine});
+
+ # copy snapshot config to current config
+ $conf = $class->__snapshot_apply_config($conf, $snap);
+ $conf->{parent} = $snapname;
+
+ # Note: old code did not store 'machine', so we try to be smart
+ # and guess the snapshot was generated with kvm 1.4 (pc-i440fx-1.4).
+ $forcemachine = $conf->{machine} || 'pc-i440fx-1.4';
+ # we remove the 'machine' configuration if not explicitly specified
+ # in the original config.
+ delete $conf->{machine} if $snap->{vmstate} && !$has_machine_config;
+ }
+
+ $class->write_config($vmid, $conf);
+
+ if (!$prepare && $snap->{vmstate}) {
+ $class->__snapshot_rollback_vm_start($vmid, $snap->{vmstate}, $forcemachine);
+ }
+ };
+
+ $class->lock_config($vmid, $updatefn);
+
+ $class->__snapshot_foreach_volume($snap, sub {
+ my ($vs, $volume) = @_;
+
+ $class->__snapshot_rollback_vol_rollback($volume, $snapname);
+ });
+
+ $prepare = 0;
+ $class->lock_config($vmid, $updatefn);
+}
+
+1;
--
2.1.4
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